1. Technical Field
This disclosure relates generally to a shaft assembly for a gas turbine engine.
2. Background Information
Most axial gas turbine engines include a high speed shaft extending between a high speed compressor section and a high speed turbine section, and a low speed shaft extending between a low speed compressor section and a low speed turbine section. The shafts extend axially and are rotatable about an axial centerline. The position of the shafts and peripheral elements surrounding the shafts are maintained by using bearings that not only permit the relative rotation, but also support loads transmitted within the engine. The cooling and lubrication of these bearings is of paramount importance to the operational ability and durability of the engine.
For performance reasons, it is desirable to increase the rotational speed of the shafts, and therefore the rotational speed of those bearing elements coupled with a shaft. Increasing the speed of the bearing, however, also increases the stress experienced by the bearing. Bearings are also subject to hoop stresses that increase as a function of diameter.
What is needed is a shaft assembly that enables a bearing to be sufficiently lubricated and cooled, one that can be utilized at higher speeds than most prior art engines, one that is configured to provide a favorable stress loading, and one that is readily manufacturable.